Wells Fargo came in as a distant second in SNL's list, at $8.3 billion. Several settlements stemmed from Charlotte-based Wachovia, which Wells scooped up during the financial crisis.

Together, the nation's six largest banks and insurance giant MetLife have been ticketed for more than $62.6 billion in legal settlements since 2010.

Still, all these settlements have had little impact on the banks' overall expenses. Even at Bank of America, litigation costs have never made up more than 2 percent of the bank's overall noninterest costs, SNL found.

Bank of America has set aside another $19 billion for potential losses on mortgage putback demands, or when securitizers attempt to force banks to buy back loans they've sold, claiming misrepresentation of their quality.

It's been this type of uncertainty that's held back the bank's stock price. Despite being the best performer in the Dow Jones Industrial Average last year, Bank of America shares are trading about a third of the price they were five years ago.